Reference is made to U.S. Pat. No. 6,483,575 issued Nov. 19, 2002, entitled AN IMAGE FORMING DEVICE AND A METHOD OF PROCESSING PHOTOSENSITIVE MEDIA HAVING MICROENCAPSULATED IMAGING MATERIAL, in the names of Loretta E. Allen, Yongcai Wang, Stephen M. Reinke and Yeh-Hung Lai; U.S. Pat. No. 6,390,694 issued May 21, 2002, entitled AN IMAGING ASSEMBLY AND MEDIA CARTRIDGE HAVING COOPERATING LINKAGE ARRANGEMENTS, in the names of Loretta E. Allen, Yongcai Wang, Stephen M. Reinke and Yeh-Hung Lai; and U.S. Pat. No. 6,268,094 issued Jul. 31, 2001, entitled A PHOTOSENSITIVE MEDIA CARTRIDGE HAVING AN AMBIENT CONDITION SENSOR, filed in the names of Loretta E. Allen, Yongcai Wang, Stephen M. Reinke and Lai Yeh-Hung.
The present invention relates to a sensor for sensing ambient conditions within a photosensitive media cartridge or at least in an environment surrounding the media or material in the cartridge. The present invention further relates to an imaging arrangement in which imaging of photosensitive material within an imaging device is controlled based on the sensed ambient conditions.
Sensing apparatuses for sensing ambient conditions such as humidity sensors are known. There are many mechanisms by which a humidity sensor senses humidity. A few examples are conductivity, capacitance, and resistivity. Humidity sensors which utilize these mechanisms are disclosed in U.S. Pat. Nos. 4,473,813, 4,298,855, 4,635,027, and 5,348,761. These commercially available humidity sensors are typically designed to have a quick response time to changes in humidity.
Image-forming devices which process a photosensitive media or material that includes microencapsulated coloring material are known. In these imaging devices the microcapsules are exposed to a radiation based on image information. The microcapsules, whose mechanical strength can change when exposed to light, are ruptured by means of a crushing pressure, whereupon the coloring material and other substances encapsulated in the microcapsules are released and development occurs. For example, some systems use a pair of upper and lower nip rollers to apply pressure. In these systems, the photosensitive media is passed between the pair of upper and lower nip rollers which apply pressure to rupture the microcapsules and begin development. Imaging devices that employ microencapsulted photosensitive compositions are disclosed in U.S. Pat. Nos. 4,399,209, 4,416,966, 4,440,846, 4,766,050, 5,783,353, and 5,916,727.
A problem in processing photosensitive media or material having microencapsulated color-forming material is that printing and/or imaging can be adversely affected by ambient conditions. That is, ambient conditions around the photosensitive media, or in the cartridge which carries the photosensitive media, can adversely affect subsequent printing or development of the image. More specifically, ambient conditions such as humidity around the photosensitive media or in the cartridge which houses the photosensitive media, can have adverse affects on the chemicals of the coloring material, the encapsulating material, and/or the photosensitive media. Further, the degree of hardening or curing of the microcapsules and the concomitant increase in viscosity of the microcapsule varies with a change in humidity. As a result, photographic characteristics such as speed, minimum and maximum density, fogging density and full color imaging can be adversely affected.
As discussed above, commercially available humidity sensors are typically designed to have a quick response time to changes in humidity. On the other hand, photosensitive media or material tends to exhibit a slow rate of response to a change in conditions. That is, photosensitive media tends to have a slow equilibrium rate. Thus, commercially available humidity sensors do not respond at the same rate as the photosensitive media or material with the result being that these sensors do not provide a true representation of the level of relative humidity on or around the media. Therefore, if a commercially available humidity sensor having a quick response to changes in humidity were associated with photosensitive media having a slow rate of change to humidity, printing parameters for the photosensitive media would not be controlled to optimum conditions. More specifically, if a commercially available humidity sensor was used to sense humidity values in a cartridge carrying photosensitive material, when the cartridge is placed in an image-forming device, the humidity sensor would respond more rapidly to humidity conditions than the photosensitive material would. Therefore, the humidity value sensed by the humidity sensor would not be representative of the humidity value around the media. The control of printing parameters would thus be based on a humidity value which is not reflective of the level of humidity on or around the media.
The present invention provides for an ambient condition sensor, such as a humidity sensor, with a response time that is equal to or matches the response time of the photosensitive media or material; a method for manufacturing the ambient condition sensor; an image-forming device which utilizes the ambient condition sensor; and a method for processing photosensitive media which overcome the above-mentioned drawbacks.
More specifically, the present invention relates to an imaging device in which photosensitive media that contains photosensitive, rupturable. microcapsules can be first exposed and then developed by applying pressure to the photosensitive media. In the image-forming device of the present invention, print image quality can be improved by sensing ambient conditions such as humidity in the image-forming device, directly from the media, or in the cartridge which carries the media, and adjusting at least one adjustable parameter based on the sensed ambient condition. As an example, in response to a sensed humidity condition, a controller or development member of the present invention can accordingly adjust the amount of pressure applied to the microcapsules.
As indicated above, in the imaging device of the present invention, the photosensitive media contains photosensitive, rupturable microcapsules that are exposed and then developed by the application of pressure using a stylus or pinch rollers to rupture unexposed microcapsules. Thereafter, the developed print may be fixed with heat supplied by a heater in the imaging device. In the invention, the level of relative humidity can be sensed inside and/or outside of the image-forming device, in the media cartridge or directly on the photosensitive media, and then at least one of the parameters of light exposure, developing pressure, printing speed or fixing temperature can be adjusted automatically on the basis of the relative humidity level to provide an improved image. As an example, by adjusting the printing speed for a printer, the so-called xe2x80x9cdark timexe2x80x9d which is the time between exposure and development will be changed. The dark time affects the hardness of microcapsules and therefore their crushability. Also, within the context of the present invention, the concept of sensing the level of relative humidity on the photosensitive media refers to sensing the moisture content on or around the photosensitive media or material.
The present invention accordingly relates to an ambient condition sensor for sensing ambient conditions in a cartridge which holds photosensitive material. The ambient condition sensor comprises a top layer, a humidity responsive layer, a conductive layer and a base support layer. In the invention, a rate of response to ambient conditions of at least one of the top layer, the humidity responsive layer, and the base support layer matches a rate of response to ambient conditions of photosensitive material in the cartridge.
The present invention further relates to a photosensitive material which comprises a transparent support layer, an imaging composition layer, a conductive layer and a base layer. The photosensitive material is positioned in a cartridge which holds photosensitive material to be developed and is adapted to sense ambient conditions around the photosensitive material in the cartridge.
The present invention further relates to a photosensitive media cartridge which comprises a housing adapted to hold a stack of photosensitive media; and an ambient condition sensor positioned within the housing for sensing ambient conditions around photosensitive media in the housing and providing an ambient condition signal indicative thereof. A development of the photosensitive media is based on the sensed ambient conditions. The ambient condition sensor comprises a transparent top layer, a humidity responsive layer, a conductive layer and a base support layer. A rate of response to ambient conditions of at least one of the transparent top layer, the humidity responsive layer, and the base support layer matches a rate of response to ambient conditions of the photosensitive media in the housing.
The present invention further relates to a photosensitive media cartridge which comprises a housing adapted to hold a stack of photosensitive media, such that at least one of the photosensitive media in the stack of photosensitive media comprises a transparent support layer, an imaging composition layer, a conductive layer and a base layer. At least one photosensitive media having the conductive layer is adapted to sense ambient conditions around the photosensitive media in said housing.
The present invention further relates to an image-forming arrangement which comprises an image-forming device for forming a latent image on a photosensitive media; and a media cartridge for holding a stack of photosensitive media therein. The media cartridge is adapted to be inserted into the image-forming device to permit a conveyance of the photosensitive media to the image-forming device. The media cartridge comprises an ambient condition sensor for sensing ambient conditions around media in the cartridge, such that a development of the photosensitive media in the image-forming device is based on the sensed ambient conditions. The ambient condition sensor comprises a transparent top layer, a humidity responsive layer, a conductive layer and a base support layer, wherein a rate of response to ambient conditions of at least one of the transparent top layer, the humidity responsive layer, and the base support layer matches a rate of response to ambient conditions of the photosensitive media in the media cartridge.
The present invention further relates to an image-forming arrangement which comprises an image-forming device for forming a latent image on a photosensitive media; and a media cartridge adapted to hold a stack of photosensitive media, wherein at least one of the photosensitive media in the stack of photosensitive media comprises a transparent support layer, an imaging composition layer, a conductive layer and a base layer. The at least one photosensitive media having the conductive layer is adapted to sense ambient conditions around the photosensitive media in the housing and a development of the photosensitive media in the image-forming device is based on the sensed ambient conditions.
The present invention further relates to a photosensitive media cartridge which comprises a housing adapted to hold a stack of photosensitive media, such that all of the media in the stack of photosensitive media comprises a transparent support layer, an imaging composition layer, a conductive layer and a base layer. The photosensitive media having the conductive layer is adapted to sense ambient conditions around the photosensitive media in said housing.
The present invention further relates to an image-forming arrangement which comprises an image-forming device for forming a latent image on a photosensitive media; and a media cartridge adapted to hold a stack of photosensitive media, wherein all of the media in the stack of photosensitive media comprises a transparent support layer, an imaging composition layer, a conductive layer and a base layer. The photosensitive media having the conductive layer is adapted to sense ambient conditions around the photosensitive media in the housing and a development of the photosensitive media in the image-forming device is based on the sensed ambient conditions.
The present invention further relates to a method of producing an ambient condition sensor for photosensitive material to be developed. The method comprises providing at least one cover layer on a conductive layer; and placing the conductive layer having at least one cover layer thereon in a cartridge which is adapted to hold photosensitive material to be developed therein, such that a rate of response to ambient conditions of at least the cover layer matches a rate of response to ambient conditions of the photosensitive material in the cartridge.
The present invention further relates to a method of controlling image development which comprises providing an ambient condition sensor in a cartridge which holds photosensitive media therein, with the ambient condition sensor sensing ambient conditions around photosensitive media in the cartridge, the ambient condition sensor comprising at least a cover layer and a conductive layer, and a rate of response to ambient conditions of at least the cover layer matches a rate of response to ambient conditions of the photosensitive media in the media cartridge; inserting the cartridge to an insertion position in an imaging device which permits a passage of photosensitive media from the cartridge to the imaging device; sensing ambient conditions around the photosensitive media by way of the ambient condition sensor; and controlling a development of images on the photosensitive media based on the sensed ambient conditions.
The present invention further relates to an ambient condition sensor for a photosensitive material imaging arrangement which comprises a cover layer and a conductive layer, wherein a rate of response to ambient conditions of the cover layer matches a rate of response to ambient conditions of a photosensitive material to be developed.